The COW Project - Ship Design

COW Design - Ship Design

Ships are designed by choosing a ship class (i.e. which role it is to be designed for) and then adding components

Ship Classes

There is a tendency for players to design homogenous ships, which is boring. One solution is to force each ship design to be allocated a role (e.g. carrier, scout, PD, etc) and then limit what players can and cant place in that ship. For example, limit the number of Beam or Missile weapons (to, say, 10% of the ship's space) that a carrier can have. However, artificial limits like these tend to get player's backs up.

A better solution is to make each ship design task specific, and give ships bonuses in performing those tasks, i.e. a specific type of ship is better suited to one role, and performs other roles less efficiently.

For example, a carrier design can carry more fighters than another class of the same size, but can only fire other weapon types with normal efficiency. Thus a carrier can still carry point defence weapons, but these will not perform as well as those on a dedicated point defence escort vessel.

There is nothing stopping a player from designing a general purpose ship, but it will not perform as well in any one role as a ship specifically designed for that task. Note, however, that a general purpose ship class (i.e. one with no bonuses) is not provided. There is no point, since there are no drawbacks in assigning a ship to a class, only positive bonuses.

Ship Class Bonuses

These percentages are subject to modification, and not all bonuses for a class may end up being used, the list is a merely list of possible bonuses which would be suited to the class. While these may seem like overly large bonuses, remember that the point of this is to encourage diversification of ship roles… so they effectively become the default levels of performance for ships of a certain role.

Role	Bonuses
Fighters
Scout	+25% Speed +25% Sensor range +100% Manoeuvrability
Interceptor	+25% Weapon Accuracy +25% Weapon Firing Rate +100% Manoeuvrability
Bomber	+50% Direct Fire Weapon Power +50% Bomb/Missile Capacity +50% Manoeuvrability
Escort Ships
Reconnaissance	+25% Sensor range +25% Speed +25% Range
Point Defence Escort	+50% Accuracy against fighters, mines, missiles.
Destroyer Escort	+25% Beam weapon capacity. +25% Beam weapon fire rate.
Capital Ships
Carrier	+25% Fighter capacity +25% Launch/refuel/land rate
Long Range Attack	+25% Direct Fire weapon capacity. +25% Direct Fire weapon accuracy against capital ships. +25% Decrease in range dissipation effects
Short Range Attack	+25% Direct Fire weapon capacity. +25% Combat speed +15% Direct Fire weapon power +15% Increase in range dissipation (to counter increased power)
Indirect Fire	+15% Missile capacity +15% Missile accuracy +15% Missile evasion +15% Missile range
Planetary Strike	+25% Bomb capacity +25% Bombing accuracy against planetary targets
System Patrol	+25% Armour Points +25% Hull Points +25% ECM
Command	All other ships in task force gain a +10% increase in their bonuses.
Non-Combat Ships
Troop Transport	+25% Troop capacity +25% Troop deployment speed (reduces deployment losses)
Colony Ship	+50% Colony Capacity

Command Ships

Command ships provide a 10% increase to the role bonuses of all ships within their task force. Note that these bonuses are not cumulative - if a task force has 2 or more command ships then the bonus increase is still only 10%, all this will achieve is a level of redundancy if a command ship is destroyed.

In addition, a command ship's bonus increase is only applied to ships of the same or smaller hull size within its task force. Thus a player cannot design a tiny, cheap command ship to provide a bonus increase to a fleet of dreadnoughts.

Note that the command bonus increase cannot be applied to capacity bonuses, since these are applied when the ship is designed, and the command bonus increase is only applied during actual combat. Thus a carrier will not directly receive much of a bonus, since its bonus is primarily capacity based. However, its fighters will gain increases to their combat bonuses - thus carriers benefit indirectly.

Crew Experience

Ship role bonuses could be tied to crew experience (if implemented). Bonuses would start at a lower level for a green grew rising up to a maximum level an elite/legendary crew:

Level	Bonus Multiplier
Green	0.33
Regular	0.67
Experienced	1.0
Veteran	1.33
Elite	1.67
Legendary	2.0

Ship Components

Each component of the ship has:

Mass
Volume
Power Requirements
Manufacturing Cost

And possibly:

Durability/Reliability/Strength (i.e. how likely the component is to be destroyed when the ship is hit)
Crew Requirements (i.e. how many crew are required to operate the component)

The mass of the ship is calculated from the hull size and the amount of armour. The mass of individual components are not calculated - the overall density of these is taken to be an average value, and thus all ships of the same hull size and armour level will be the same mass.

Hull

The hull defines the basic characteristics and size of the ship.

The Hull size determines how much stuff can be fitted inside the ship, and how much damage the ship can take (hit points). The material of the hull determines the mass (affecting engine size) and strength (affecting hit points) of the hull. The hull can be reinforced to provide additional hitpoints, though this takes up internal space within the hull.

There is currently no upper limit on ship size. Hulls start at size 1, and increase in steps by Ö2 each time. However there is an increasing penalty for building ships of too large a size - once a ship is larger than the shipyard which is building it, its cost and construction time start to increase exponentially. And shipyards are exponentially more expensive (and more time consuming) to build as they increase in size.

Hull capacity = SQRT(2) ^ (hull size - 1)

Armour

Armour provides an additional level of protection to the hull. Armour does not take up external space, but does have mass, and thus additional engine capacity would be required in order to maintain the same speed/range.

The material of the armour determines its mass and effectiveness. Each material has a base strength below which it cannot be damaged. The thickness of the armour (i.e. the number of layers) can be increased meaning that more hits are required to penetrate the armour and damage the hull/internals.

Power Plant

This provides power for weapons, shields, engines, sensors, life support etc. The size of this is determined automatically as power consuming components are added to the ship.

Interstellar Engines

These determine speed of travel between stars, and the maximum range of any one jump. Multiple types of engine may be possible, e.g. free ranging, or starlane/wormhole only. Depending on the technology, it may be possible to increase speed and/or range, which will increase the size and power consumption of the engines.

System Engines

These determine combat speed, and thus affect evasion capability. System engine size is calculated automatically based on a speed requirement specified by the player.

Manoeuvring Engines/Gyros

These are based on the same technology as the system engines, but are used to help the ship turn. This determines manoeuvrability, which in turn defines combat evasiveness and accuracy.

Shields

Shields behave differently to armour in that they do not leave 'holes' where they are hit, but are instead drained overall by each hit. Factors influencing the effectiveness of a shield include:

Type of Shield (reflective, damping)
Shield Thickness / Power Level
Shield Recharge Rate.

Sensors & Stealth

Sensors determine the base detection, identification, and targeting ranges of a ship. This, in conjunction with the target ships size and stealth levels give the actual detection range between ships.

There are 3 ranges associated with each sensor.

Detection range : The range at which an enemy ship can be detected.
Identification range : The range at which the type and number of enemy ships in a taskforce can be determined.
Targetting range : The range at which a lock is achieved for sucessful weapons fire.

There are 2 main types of sensors : passive and active.

Active Sensors:

Emit a signal and recieve an echo.
Longer range than passive sensors.
Identification range is by default 66% of the detection range.
Targetting range is by default 50% of the detection range.
Much more likely to detect stealthy ships than passive sensors.
Make the host ship much easier to spot, especially to ships with passive sensors.
Generally smaller and cheaper than passive sensors.

Passive Sensors:

These sensors do not emit any signals, they just listen for emissions from enemy ships.
Detection range is dependent on the emission levels of the enemy ships.
Generally have a shorter effective range than active sensors.
Identification range is by default 50% of the detection range.
Targetting range is by default 25% of the detection range
Do not make host ship any easier to detect when in use, therefore useful for creating stealthed ships.
Generally ineffective when detecting stealthed enemy ships, since these ships usually have a high passive stealth rating.

Any ship has 2 stealth ratings : passive and active

Passive stealth rating:

This is the detectability of a ship to a passive sensor, i.e. its 'quietness'.
This is based on the level of emissions from the ship itself.
The higher the rating, the harder the ship is to detect with passive sensors.
When firing weapons, a ships passive stealth rating drops drastically.

Passive stealth rating can be increased by:

Using larger, more expensive, stealthed versions of ship components in ship construction.
Not using active sensors.
Adding signal damping fields to the ship's internals.
Not firing weapons.

Active stealth rating:

This is the detectability of a ship to an active sensor, i.e. its 'reflectivity'.
The higher the rating, the harder the ship is to detect with active sensors.

Active stealth rating can increased by:

Using signal absorbing materials in the ships hull and armour.
Using signal damping fields on the outside of the ship (i.e. cloaking fields).

ECM & ECCM

ECM technologies are active systems which interfere with enemy sensors making the ship harder to target and hit. They do NOT increase detection ranges, in fact they significantly decrease them because they are a significant signal output from a ship. What they do is decrease targetting range and enemy weapon accuracy.

ECCM is used to counter the effects of ECM. It does not increase the base detection range of a ship, it only cancels out some or all of the effects of enemy ECM. Thus the detection range may be returned to its original value, but it will not fall below this. If there is no enemy ECM present, then the ECCM will have no effect.

Crew

Crew take up space (working space and living quarters) and power (life support).

Command staff - i.e. the people who control the ship.
Engineering - affects ability to withstand and repair damage.
Barracks - fighter pilots and combat troops for boarding actions.

The player doesn't directly pick crew numbers - these are calculated automatically based on the types and number of weapons/specials that the player adds to the ship design. Life Support and space requirements for crew are also automatically calculated. Multiple redundant life support systems are possible. These take more space, but decrease the chance of a critical hit destroying life support and killing the crew (and thus the ship).

Weapons

Weapons are designed separately, then added to the ship in whatever quantity the player chooses (or as many as can be fitted). For missiles the player must specify both the number of launchers + the number of reloads.

Specific designs of fighter are not designed into the ship. Instead, overall fighter capacity is defined (i.e. the number of hull sizes which can be carried). The number of launch tubes and landing bays determine the rate at which fighters can be launched & retrieved.

See the Weapon Design section for more detail.

Specials

There are all sorts of specials which can be added, some of which are mission based

Colony Pod - for colony ships (duh).
Launch Bays - determine rate at which carried fighters can be launched/retrieved.
Engineering bays - affects ability to withstand and repair damage

Limited Ship Designs

Given the opportunity, players have a tendency to redesign every ship in their entire fleet every time a new type of coffee-cup holder is researched. This is expected, because players naturally want any new ships they build to incorporate all of the newest techs available to them. However, this tends to encourage the scenario found in Moo3, where players were forced (or forced themselves) to redesign their entire fleet every turn.

To avoid this problem, and to make the game more interesting (by forcing the player to make hard decisions about when to upgrade), methods will be imposed to limit the number of concurrent ship designs of each class. Several approaches are possible:

1: Hard limits on the number of concurrent ship designs. This is similar to the approach used in Moo1, but instead of a limit of 6 designs overall, there would be a limit of two or three designs for each ship class. This should be sufficient to have one or two designs of each class in active service, while production of the latest designs is ramped up. This achieves the desired effect, but its probably better to try and achieve the same effect through gentle persuasion rather than hard limits.

2: Prototyping Costs. This would take the form of higher costs for the first ship (or n ships) of a given design. This is likely to be insufficient on its own, as it would be cripplingly expensive in the early game, but would become increasingly irrelevant as the player's production capability increases.

3: Maintenance Costs. Maintenance costs would be increased across the board as the player has more and more concurrent ship designs. This works well because it takes into account the quantities of ships as well as the number of designs. The relationship will be designed so that a player is not penalised for having a few designs (2 or 3), but becomes progressively harsher as the number of designs increases.

Option 3 is the approach that will be taken. The relationship between the number of concurrent designs in a class and the maintenance cost multiplier for all ships of that class is as follows:

Number of Designs	Maintenance Cost Multiplier
1	1.0
2	1.1
3	1.2
4	1.5
5	2.0
Over 5	(Designs - 1) / 2

Ship Crew Experience

Currently the plan is that ship crew experience will not be implemented in the game.

This is because if it was implemented, then every ship in the game would have to be tracked individually. This would be a major programming headache, and is completely at odds with the current design, based on large fleets of ships.

Refitting

Ship refitting will not be included in the game. It encourages boring, homogenous fleets. The only real reason to include it would be if ship crew experience was to be implemented. And it's not.

Fighters

Fighters are designed in the same way as capital ships, but have size limitations imposed on them - fighters cannot go beyond a hull capacity of 2.0. However, fighters have certain performance advantages over capital ships, due to their small size and limited endurance requirements (fighters do not need long-term fuel supplies or life support), and do not require interstellar engines. In addition, fighters do not require launchers for bombs and missiles (they tend to be single shot, externally mounted) and have enhanced manoeuvrability due to their small size.

Fighter bonuses and limitations:

Maximum hull size of 2.
Maximum crew size of 2.
Power plant size halved.
Bridge size and power requirements quartered.
Life support size and power requirements quartered.
Do not require launchers for bombs and missiles.
Cannot be fitted with interstellar engines.
Enhanced manoeuvrability (see ship class bonuses).

Due to the limitations in hull sizes, hull sizes are increased in smaller steps than for capital ships.

Hull Capacity = SQRT(SQRT(2)) ^ (hull size - 1) (gives 5 sizes from 1.0 to 2.0 capacity)
Or
Hull Capacity = SQRT(SQRT(SQRT(2))) ^ (hull size - 1) (gives 9 sizes from 1.0 to 2.0 capacity)

Ship Design Calculations

Items in italics are external inputs, derived from player choices or technology tables.

Construction

Valid Design = ( Hull Size >= Sum of sizes of all other components on the ship )

Construction Cost = Total Cost * Oversize Factor

Total Cost = Sum of all component costs on the ship.

Oversize Factor = Hull Size / Construction Yard Size (minimum value 1.0)

Size and Mass

Note that armour does not directly subtract from the space inside the hull, however, it increases the mass of the ship, and so the engine sizes will increase in order to maintain the required ship speed.

Hull Cost = Material Cost * Hull Size

Armour Cost = Material Cost * Hull Size * Thickness

Total Mass of Ship = Mass of Hull + Mass of Armour

Mass of Hull = Material Mass * Hull Size * Level of Reinforcement

Mass of Armour = Material Mass * Hull Size * Thickness

Power

Power Plant Cost = Power Plant Technology Cost * Power Plant Size

Power Plant Size = Power Plant Technology Size * Total Power Requirements

Total Power Requirements = Sum of power requirements of all components on the ship

Movement

Note : for interstellar engine calculations size and power requirements go up linearly with range, but go up exponentially with speeds above the tech's base speed.

System Engine Cost = System Engine Tech Cost * System Engine Size

System Engine Size = System Engine Tech Size * System Engine Power

System Engine Power = System Engine Tech Power * Combat Speed * Total Mass of Ship

Interstellar Engine Cost = Interstellar Engine Tech Cost * Interstellar Engine Size

Interstellar Engine Size = Interstellar Engine Tech Size * Interstellar Engine Power

Interstellar Engine Power = Interstellar Engine Tech Power * Range Factor * Speed Factor * Total Mass of Ship

Range Factor = Travel Range / Interstellar Engine Tech Base Range (minimum value of 1.0)

Speed Factor = (Travel Speed / Interstellar Engine Tech Base Speed) ^ 2 (minimum value of 1.0)

Manoeuvrability

Note that smaller ships are inherently more manoeuvrable than large ones (i.e. the size of manoeuvring engines goes up exponentially with ship size). This is to counter the shield power advantage of larger ships (shield size = sqrt(hull size)).

Manoeuvre Engine Cost = System Engine Tech Cost * Manoeuvre Engine Size

Manoeuvre Engine Size = System Engine Tech Size * Manoeuvre Engine Power

Manoeuvre Engine Power = System Engine Tech Power * Ship Manoeuvre Capability * (Total Mass of Ship ^ 2)

Manoeuvrability = Ship Manoeuvre Capability
Or = Crew Manoeuvrability Limit (whichever is smallest)

Crew Manoeuvrability Limit = Species Physical Limit * Damping Technology Effects

Note that Species Physical Limit can change after the ship has been designed, and thus the Crew Manoeuvrability Limit (and thus the actual ship Manoeuvrability) should be recalculated as is necessary.

Sensors

Sensor Cost = Sensor Tech Cost * Sensor Size

Sensor Size = Sensor Tech Size * Sensor Power

Sensor Power = Sensor Tech Power * Sensor Range Factor

Sensor Range Factor = (Sensor Range / Sensor Tech Base Range) ^ 2 (minimum value of 1.0)

Cloaking

Cloak Cost = Cloak Tech Cost * Cloak Size

Cloak Size = Cloak Tech Size * Cloak Power

Cloak Power = Cloak Tech Power * Stealth Level * Hull Size

Accuracy & Evasion

Long Range Accuracy = Weapon Tech Accuracy * Sensor Range

Short Range Accuracy = Weapon Tech Accuracy * Weapon Tracking Rate

Weapon Tracking Rate = Manoeuvrability Or = Turret Tracking Rate (whichever is greater)

Long Range Evasion = (Stealth Level * Combat Speed) / Hull Size

Short Range Evasion = (Manoeuvrability * Combat Speed) / Hull Size

Shields

Shield Generator Cost = Shield Tech Cost * Shield Generator Size

Shield Generator Size = Shield Tech Size * Shield Generator Power

Shield Generator Power = Shield Tech Power * (Shield Thickness ^ 2) * (Recharge Rate ^ 2) * SQRT(Hull Size)

Life Support

Life Support Cost = Life Support Tech Cost * Life Support Size

Life Support Size = Life Support Tech Size * Life Support Power

Life Support Power = Life Support Tech Power * Number of Crew * Species Individual Size

Number of Crew = Ship Class Crew Factor * Automation Tech Factor * Hull Size